The present invention relates to a peripheral data acquisition, monitor, and control device for use with a personal computer (PC) having a detachable keyboard, the output from the device emulating, in every respect, the signals transmitted to the computer during the operation of inputting values via the keyboard. More specifically, the peripheral data acquisition, monitor, and control device comprises an Input/Output (I/O) Bridge device including programmable circuitry which allows data supplied thereto and fed therethrough, such as measurement data, to be entered directly into programs designed for keyboard entry only, with no keyboard entry being made, and with no reprogramming of the computer, to which the data is being fed, being necessary.
Heretofore, it has been proposed to provide computer controlled data acquisition systems which are designed to automate every step in a particular process. An example of such an automated process would be a production sorting system where products are tested under computer control to see if the products are within limits for certain parameters; and if they are not, they are rejected by the computer. Such a system tends to be expensive, bulky, and of limited utility outside of the narrow use for which it was designed.
There has also been a trend to develop data acquisition accessories for use with desktop computers, which have become very popular. Such accessories (either proposed or developed) consist of plug-in circuit cards which are connectable to the computer's central processing unit (CPU) and are dependent upon the computer as a power source therefor. Special programs must be written to set up the circuit card to take a particular measurement and forward it to the CPU so the measurement either can be saved on a disc storage unit or displayed on a video monitor. While such method reduces the tedium associated with reading and recording measured values and the possibility of errors in such reading and recording, it still has a drawback--that of requiring specialized knowledge and the ability to program the CPU and the data acquisition circuit card in order to perform the desired functions. A further difficulty is encountered in that existing software programs for performing data reduction and analysis based on keyboard entry of data must be modified, or even rewritten, in order to accept input from the data acquisition circuit card.
With the advent of computers having a detachable keyboard including its own microcontroller, and with the keyboard being connected to the CPU by a single cable incorporating a power supply line, a ground line for the keyboard, and a bidirectional data line therefor, it has become possible to develop a device which is connectable between the keyboard and the CPU which can emulate keystrokes for inputting data.
As will be described in greater detail below, the Input/Output Bridge device of the present invention provides a means for acquisition of measurement data and transference of such data to a central processing unit in a manner which, in every respect, emulates the operation of typing in values via a keyboard. In other words, the present invention allows measurement data being input thereto to be modified therein, as required, and then output therefrom, directly into programs designed for keyboard entry only in a manner which completely emulates such keyboard entry, without the need of keyboard entry of such data and without the need of modifying or rewriting existing programs to accept such input.